<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../react18/react.development.js"></script>
  <script src="../react18/react-dom.development.js"></script>
  <script src="../react18/babel.min.js"></script>
</head>
<body>
    <button id="btn">修改vDOM,并重新渲染</button>
    <div id="app"></div>
    <script type="text/babel">
        const arr=[1,22,333,4444,55555]
        const vDOM=(
            <ul>
                {
                arr.map(item => (<li>{item}</li>))    
                }
            </ul>
        )


        const root = ReactDOM.createRoot(document.getElementById('app'))
        root.render(vDOM)


        const oBtn = document.getElementById('btn');
        let i = 0;
        oBtn.onclick=function(){
            arr.unshift('666666'+ i++)
            const vDOM=(
            <ul>
                {
                    arr.map(item => (<li>{item}</li>)) 
                }
            </ul>
        )
        root.render(vDOM)
        }
    </script>
</body>
</html>